title: Excitation of Limulus photoreceptors by vanadate and by a hydrolysis-resistant analog of guanosine triphosphate.
abstract: Discrete voltage fluctuations that occur spontaneously or in response to dim lights can be recorded from the ventral photoreceptors of Limulus. The injection of vanadate or the hydrolysis-resistant analog of guanosine triphosphate, GTP-gamma-S, into ventral photoreceptors induces the production of discrete waves in the dark. The chemically induced discrete waves are similar to those induced by light. Ventral photoreceptors may contain a guanyl nucleotide binding protein whose activation by vanadate or GTP-gamma-S induces the discrete waves.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000262:Adenylyl Cyclases / Q000378:metabolism / Q000502:physiology; D000818:Animals; D002352:Carrier Proteins / Q000502:physiology; D004789:Enzyme Activation / Q000187:drug effects; D005459:Fluorides / Q000494:pharmacology; D019204:GTP-Binding Proteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000502:physiology; D006737:Horseshoe Crabs / Q000502:physiology*; D010786:Photoreceptor Cells / Q000187:drug effects*; D013873:Thionucleotides / Q000494:pharmacology*; D014638:Vanadates; D014639:Vanadium / Q000494:pharmacology*
chemical_list: D002352:Carrier Proteins; D013873:Thionucleotides; D014639:Vanadium; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D014638:Vanadates; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D005459:Fluorides